AmpRx The Brownie Input Voltage Attenuator
The Brownie is a voltage optimizing power supply (aka a voltage controller) designed specifically for modern tube amplifiers, offering the ultimate solution for achieving consistent tone and protecting valuable equipment—the first of its kind.
If you care about getting the most out of your tube amp, and protecting it, the Brownie by AmpRx is a game changer. We're big fans of AmpRx's gear, and this little box shows exactly why: compact, smart, and built to make your amp sound and feel its best.
Why the Brownie is a must-have
Precision Voltage Control: The Brownie lets you both drop and boost your voltage. Dial it in volt-by-volt: decrease in -1V steps (down to -7V) or increase in +3V or +5V steps.
Better Tone, Consistently: By optimizing voltage, you can hit your amp's "sweet spot". That means more consistent tone, whether you're gigging or practicing.
Protects Your Gear: The Brownie safeguards your rig by ensuring your tubes get the right voltage time after time, helping to improve tube life and prevent costly amp repairs.
Built Tough, Made in the USA: Hand-wired by humans in the U.S., with a rugged metal housing that's road-ready.
Tailored for Tube Amps: AmpRx custom wound the transformer specifically for tube amplifiers. No generic parts.
Flexible Fuse Options: Comes with both 2A and 4A fuse options, so you can match the Brownie to your amplifier's needs.
Portable: Weighs in at only ~2.8 lb and compact enough to fit on a pedalboard or into a small gig bag.
Specs at a Glance
- Input: 120 V / 50–60 Hz (standard IEC AC)
- Adjustment Range: -7V (via -1V steps) to +5V (+3V / +5V)
- Max Load: 4A / 480W (with 4A fuse)
- Dimensions: ~5-3/4" × 4" × 4-1/8" (146mm x 101mm x 105mm)
- Weight: ~2.8 lb (1.27 kg)
- Build: Rugged metal case, powder-coated in the USA
Why we (seriously) love AmpRx
AmpRx has earned a reputation among amp techs, touring artists, and serious gearheads for making tools that actually improve the way amps perform. Their products show up on tour rigs and backstage setups—they don't just make gear; they make solutions. The Brownie is a testament to that ethos: thoughtful, effective, and built to last.
